1. Field of the Invention
This invention relates to a system for controlling the ignition timing in an internal combustion engine, and, more particularly, it is concerned with an ignition timing control system for an internal combustion engine, which is capable of detecting a quantity of intake air into the combustion engine by means of an intake air quantity sensor, and controlling the ignition timing of the internal combustion engine based on the output as detected by the intake air quantity sensor and the number of revolution of the engine.
2. Discussion of Background
It has so far been a practice that, when the ignition timing of internal combustion engine is to be controlled, the intake air quantity sensor or air flow sensor (hereinafter abbreviated as "AFS") is disposed upstream the throttle valve, and, on the basis of an intake air quantity A/N (also abbreviated as "AN") per single suction of the engine as calculated from an output of this AFS and the number of revolution of the engine, the ignition timing of the internal combustion engine is controlled.
With the above-mentioned conventional control system, however, there was a point of problem such that the ignition timing shifts to the side of the advance angle of the engine by its demand, thereby causing the engine knocking, because of delay in processing of the arithmetic operations for the intake air quantity A/N at the transition of the engine revolution, e.g., at the time of speed acceleration, or detection by AFS of the intake air quantity at a rate lower than its actual quantity.